July 31, 2011
Type 2
Question from India:
Persistent hyperglycemia seems to be common in insulin resistant diabetics in spite of taking insulin. One action of insulin is that it enhance energy stores–glycogen, fats, etc. and resist their breakdown. While constant insulin can be present, in insulin resistant cases either due to persistent high glucose level or injected insulin WHICH may suggest increased energy stores and a resistance in their breakdown. If so, how will glucose be available on an increased or urgent need if energy stores are resisted? I assume that the body may be securing it by keeping a high blood glucose level (may be visceral fats also) OR high blood glucose is somewhat acting as an energy store because other energy stores are resisting due to high insulin levels. Such a high level can also be dependent on daily or average use and need of glucose. If one starts exercising or other physical activity, his need for glucose increases, so he may need more glucose store to be maintained–resulting in still higher blood glucose levels. It may also expressed as so-called insulin resistance. This is probably a sedentary lifestyle or laziness in diabetics. Maybe there needs to be a reduced glucose need so that the body may not need to maintain very high blood glucose levels in this thought. Though it looks quite logical, will you tell me accordingly?
Answer:
When you exercise, you activate the sympathetic nervous system with an appropriate increase in epinephrine and glucagon. This results in rapid insulin resistance and switches the flux of glucose from glycogen storage and anabolism to hepatic glucose output and elevated glucose levels. In essence, there is induction of more insulin resistance so as to make available fuel for exercise. If glucose goes on for a while and energy stores are used, gluconeogenesis increases from breakdown products, such as amino acids and lactate.
JTL
